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Nullifier

Defined in: lib/provable/crypto/nullifier.ts:20

Nullifiers are used as a public commitment to a specific anonymous account, to forbid actions like double spending, or allow a consistent identity between anonymous actions.

RFC: https://github.com/o1-labs/o1js/issues/756

Paper: https://eprint.iacr.org/2022/1255.pdf

Extends​

Constructors​

Constructor​

new Nullifier(value: {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}): Nullifier;

Defined in: lib/provable/types/struct.ts:133

Parameters​

value​
private​

{ c: Field; g_r: Group; h_m_pk_r: Group; } = ...

private.c​

Field = Field

private.g_r​

Group = Group

private.h_m_pk_r​

Group = Group

public​

{ nullifier: Group; s: Scalar; } = ...

public.nullifier​

Group = Group

public.s​

Scalar = Scalar

publicKey​

Group = Group

Returns​

Nullifier

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).constructor

Properties​

private​

private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};

Defined in: lib/provable/crypto/nullifier.ts:26

c​

c: Field = Field;

g_r​

g_r: Group = Group;

h_m_pk_r​

h_m_pk_r: Group = Group;

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).private

public​

public: {
nullifier: Group;
s: Scalar;
};

Defined in: lib/provable/crypto/nullifier.ts:22

nullifier​

nullifier: Group = Group;

s​

s: Scalar = Scalar;

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).public

publicKey​

publicKey: Group = Group;

Defined in: lib/provable/crypto/nullifier.ts:21

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).publicKey

_isStruct​

static _isStruct: true;

Defined in: lib/provable/types/struct.ts:133

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
})._isStruct

check()​

static check: (value: {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}) => void;

Defined in: lib/provable/types/provable-intf.ts:76

Add assertions to the proof to check if value is a valid member of type T. This function does not return anything, instead it creates any number of assertions to prove that value is a valid member of the type T.

For instance, calling check function on the type Bool asserts that the value of the element is either 1 or 0.

Parameters​

value​

the element of type T to put assertions on.

private​

{ c: Field; g_r: Group; h_m_pk_r: Group; } = ...

private.c​

Field = Field

private.g_r​

Group = Group

private.h_m_pk_r​

Group = Group

public​

{ nullifier: Group; s: Scalar; } = ...

public.nullifier​

Group = Group

public.s​

Scalar = Scalar

publicKey​

Group = Group

Returns​

void

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).check

empty()​

static empty: () => {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
};

Defined in: lib/provable/types/struct.ts:143

Returns​

{
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}
private​
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
private.c​
c: Field = Field;
private.g_r​
g_r: Group = Group;
private.h_m_pk_r​
h_m_pk_r: Group = Group;
public​
public: {
nullifier: Group;
s: Scalar;
};
public.nullifier​
nullifier: Group = Group;
public.s​
s: Scalar = Scalar;
publicKey​
publicKey: Group = Group;

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).empty

fromFields()​

static fromFields: (fields: Field[]) => {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
};

Defined in: lib/provable/types/provable-intf.ts:115

Parameters​

fields​

Field[]

Returns​

{
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}
private​
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
private.c​
c: Field = Field;
private.g_r​
g_r: Group = Group;
private.h_m_pk_r​
h_m_pk_r: Group = Group;
public​
public: {
nullifier: Group;
s: Scalar;
};
public.nullifier​
nullifier: Group = Group;
public.s​
s: Scalar = Scalar;
publicKey​
publicKey: Group = Group;

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).fromFields

fromValue​

static fromValue: (x: 
| {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}
| {
private: {
c: bigint;
g_r: {
x: bigint;
y: bigint;
};
h_m_pk_r: {
x: bigint;
y: bigint;
};
};
public: {
nullifier: {
x: bigint;
y: bigint;
};
s: bigint;
};
publicKey: {
x: bigint;
y: bigint;
};
}) => {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
} & (value: {
private: {
c: string | number | bigint | Field;
g_r: | Group
| {
x: number | bigint | Field;
y: number | bigint | Field;
};
h_m_pk_r: | Group
| {
x: number | bigint | Field;
y: number | bigint | Field;
};
};
public: {
nullifier: | Group
| {
x: number | bigint | Field;
y: number | bigint | Field;
};
s: bigint | Scalar;
};
publicKey: | Group
| {
x: number | bigint | Field;
y: number | bigint | Field;
};
}) => {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
};

Defined in: lib/provable/types/provable-intf.ts:86

Convert provable type from a normal JS type.

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).fromValue

toAuxiliary()​

static toAuxiliary: (value?: {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}) => any[];

Defined in: lib/provable/types/provable-intf.ts:47

A function that takes value (optional), an element of type T, as argument and returns an array of any type that make up the "auxiliary" (non-provable) data of value.

Parameters​

value?​

the element of type T to generate the auxiliary data array from, optional. If not provided, a default value for auxiliary data is returned.

private​

{ c: Field; g_r: Group; h_m_pk_r: Group; } = ...

private.c​

Field = Field

private.g_r​

Group = Group

private.h_m_pk_r​

Group = Group

public​

{ nullifier: Group; s: Scalar; } = ...

public.nullifier​

Group = Group

public.s​

Scalar = Scalar

publicKey​

Group = Group

Returns​

any[]

An array of any type describing how this T element is made up of "auxiliary" (non-provable) data.

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).toAuxiliary

toCanonical()?​

static optional toCanonical: (x: {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}) => {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
};

Defined in: lib/provable/types/provable-intf.ts:104

Optional method which transforms a provable type into its canonical representation.

This is needed for types that have multiple representations of the same underlying value, and might even not have perfect completeness for some of those representations.

An example is the ForeignField class, which allows non-native field elements to exist in unreduced form. The unreduced form is not perfectly complete, for example, addition of two unreduced field elements can cause a prover error.

Specific protocols need to be able to protect themselves against incomplete operations at all costs. For example, when using actions and reducer, the reducer must be able to produce a proof regardless of the input action. toCanonical() converts any input into a safe form and enables us to handle cases like this generically.

Note: For most types, this method is the identity function. The identity function will also be used when the toCanonical() is not present on a type.

Parameters​

x​
private​

{ c: Field; g_r: Group; h_m_pk_r: Group; } = ...

private.c​

Field = Field

private.g_r​

Group = Group

private.h_m_pk_r​

Group = Group

public​

{ nullifier: Group; s: Scalar; } = ...

public.nullifier​

Group = Group

public.s​

Scalar = Scalar

publicKey​

Group = Group

Returns​

{
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}
private​
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
private.c​
c: Field = Field;
private.g_r​
g_r: Group = Group;
private.h_m_pk_r​
h_m_pk_r: Group = Group;
public​
public: {
nullifier: Group;
s: Scalar;
};
public.nullifier​
nullifier: Group = Group;
public.s​
s: Scalar = Scalar;
publicKey​
publicKey: Group = Group;

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).toCanonical

toFields()​

static toFields: (value: {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}) => Field[];

Defined in: lib/provable/types/provable-intf.ts:36

A function that takes value, an element of type T, as argument and returns an array of Field elements that make up the provable data of value.

Parameters​

value​

the element of type T to generate the Field array from.

private​

{ c: Field; g_r: Group; h_m_pk_r: Group; } = ...

private.c​

Field = Field

private.g_r​

Group = Group

private.h_m_pk_r​

Group = Group

public​

{ nullifier: Group; s: Scalar; } = ...

public.nullifier​

Group = Group

public.s​

Scalar = Scalar

publicKey​

Group = Group

Returns​

Field[]

A Field array describing how this T element is made up of Field elements.

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).toFields

toInput()​

static toInput: (x: {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}) => {
fields?: Field[];
packed?: [Field, number][];
};

Defined in: lib/provable/types/struct.ts:137

Parameters​

x​
private​

{ c: Field; g_r: Group; h_m_pk_r: Group; } = ...

private.c​

Field = Field

private.g_r​

Group = Group

private.h_m_pk_r​

Group = Group

public​

{ nullifier: Group; s: Scalar; } = ...

public.nullifier​

Group = Group

public.s​

Scalar = Scalar

publicKey​

Group = Group

Returns​

{
fields?: Field[];
packed?: [Field, number][];
}
fields?​
optional fields: Field[];
packed?​
optional packed: [Field, number][];

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).toInput

toJSON()​

static toJSON: (x: {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}) => {
private: {
c: string;
g_r: {
x: string;
y: string;
};
h_m_pk_r: {
x: string;
y: string;
};
};
public: {
nullifier: {
x: string;
y: string;
};
s: string;
};
publicKey: {
x: string;
y: string;
};
};

Defined in: lib/provable/types/struct.ts:141

Parameters​

x​
private​

{ c: Field; g_r: Group; h_m_pk_r: Group; } = ...

private.c​

Field = Field

private.g_r​

Group = Group

private.h_m_pk_r​

Group = Group

public​

{ nullifier: Group; s: Scalar; } = ...

public.nullifier​

Group = Group

public.s​

Scalar = Scalar

publicKey​

Group = Group

Returns​

{
private: {
c: string;
g_r: {
x: string;
y: string;
};
h_m_pk_r: {
x: string;
y: string;
};
};
public: {
nullifier: {
x: string;
y: string;
};
s: string;
};
publicKey: {
x: string;
y: string;
};
}
private​
private: {
c: string;
g_r: {
x: string;
y: string;
};
h_m_pk_r: {
x: string;
y: string;
};
};
private.c​
c: string = Field;
private.g_r​
g_r: {
x: string;
y: string;
} = Group;
private.g_r.x​
x: string;
private.g_r.y​
y: string;
private.h_m_pk_r​
h_m_pk_r: {
x: string;
y: string;
} = Group;
private.h_m_pk_r.x​
x: string;
private.h_m_pk_r.y​
y: string;
public​
public: {
nullifier: {
x: string;
y: string;
};
s: string;
};
public.nullifier​
nullifier: {
x: string;
y: string;
} = Group;
public.nullifier.x​
x: string;
public.nullifier.y​
y: string;
public.s​
s: string = Scalar;
publicKey​
publicKey: {
x: string;
y: string;
} = Group;
publicKey.x​
x: string;
publicKey.y​
y: string;

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).toJSON

toValue()​

static toValue: (x: {
private: {
c: Field;
g_r: Group;
h_m_pk_r: Group;
};
public: {
nullifier: Group;
s: Scalar;
};
publicKey: Group;
}) => {
private: {
c: bigint;
g_r: {
x: bigint;
y: bigint;
};
h_m_pk_r: {
x: bigint;
y: bigint;
};
};
public: {
nullifier: {
x: bigint;
y: bigint;
};
s: bigint;
};
publicKey: {
x: bigint;
y: bigint;
};
};

Defined in: lib/provable/types/provable-intf.ts:81

Convert provable type to a normal JS type.

Parameters​

x​
private​

{ c: Field; g_r: Group; h_m_pk_r: Group; } = ...

private.c​

Field = Field

private.g_r​

Group = Group

private.h_m_pk_r​

Group = Group

public​

{ nullifier: Group; s: Scalar; } = ...

public.nullifier​

Group = Group

public.s​

Scalar = Scalar

publicKey​

Group = Group

Returns​

{
private: {
c: bigint;
g_r: {
x: bigint;
y: bigint;
};
h_m_pk_r: {
x: bigint;
y: bigint;
};
};
public: {
nullifier: {
x: bigint;
y: bigint;
};
s: bigint;
};
publicKey: {
x: bigint;
y: bigint;
};
}
private​
private: {
c: bigint;
g_r: {
x: bigint;
y: bigint;
};
h_m_pk_r: {
x: bigint;
y: bigint;
};
};
private.c​
c: bigint = Field;
private.g_r​
g_r: {
x: bigint;
y: bigint;
} = Group;
private.g_r.x​
x: bigint;
private.g_r.y​
y: bigint;
private.h_m_pk_r​
h_m_pk_r: {
x: bigint;
y: bigint;
} = Group;
private.h_m_pk_r.x​
x: bigint;
private.h_m_pk_r.y​
y: bigint;
public​
public: {
nullifier: {
x: bigint;
y: bigint;
};
s: bigint;
};
public.nullifier​
nullifier: {
x: bigint;
y: bigint;
} = Group;
public.nullifier.x​
x: bigint;
public.nullifier.y​
y: bigint;
public.s​
s: bigint = Scalar;
publicKey​
publicKey: {
x: bigint;
y: bigint;
} = Group;
publicKey.x​
x: bigint;
publicKey.y​
y: bigint;

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).toValue

Methods​

assertUnused()​

assertUnused(witness: MerkleMapWitness, root: Field): void;

Defined in: lib/provable/crypto/nullifier.ts:128

Checks if the Nullifier has been used before.

Parameters​

witness​

MerkleMapWitness

root​

Field

Returns​

void

Example​

// asserts that the nullifier has not been used before, throws an error otherwise
nullifier.assertUnused();

getPublicKey()​

getPublicKey(): PublicKey;

Defined in: lib/provable/crypto/nullifier.ts:157

Returns the PublicKey that is associated with this Nullifier.

Returns​

PublicKey

Example​

let pk = nullifier.getPublicKey();

isUnused()​

isUnused(witness: MerkleMapWitness, root: Field): Bool;

Defined in: lib/provable/crypto/nullifier.ts:108

Returns the state of the Nullifier.

Parameters​

witness​

MerkleMapWitness

root​

Field

Returns​

Bool

Example​

// returns a Bool based on whether or not the nullifier has been used before
let isUnused = nullifier.isUnused();

key()​

key(): Field;

Defined in: lib/provable/crypto/nullifier.ts:95

The key of the nullifier, which belongs to a unique message and a public key. Used as an index in Merkle trees.

Returns​

Field

Example​

// returns the key of the nullifier which can be used as index in a Merkle tree/map
let key = nullifier.key();

setUsed()​

setUsed(witness: MerkleMapWitness): Field;

Defined in: lib/provable/crypto/nullifier.ts:143

Sets the Nullifier, returns the new Merkle root.

Parameters​

witness​

MerkleMapWitness

Returns​

Field

Example​

// calculates the new root of the Merkle tree in which the nullifier is set to used
let newRoot = nullifier.setUsed(witness);

verify()​

verify(message: Field[]): void;

Defined in: lib/provable/crypto/nullifier.ts:47

Verifies that the Nullifier belongs to a specific message. Throws an error if the Nullifier is incorrect.

Parameters​

message​

Field[]

Returns​

void

Example​

let nullifierMessage = [voteId, ...otherData];
// throws an error if the nullifier is invalid or doesn't belong to this specific message
nullifier.verify(nullifierMessage);

createTestNullifier()​

static createTestNullifier(message: Field[], sk: PrivateKey): Nullifier;

Defined in: lib/provable/crypto/nullifier.ts:170

Note: This is not the recommended way to create a Nullifier in production. Please use mina-signer to create Nullifiers. Also, this function cannot be run within provable code to avoid unintended creations of Nullifiers - a Nullifier should never be created inside provable code (e.g. a smart contract) directly, but rather created inside the users wallet (or other secure enclaves, so the private key never leaves that enclave).

PLUME: An ECDSA Nullifier Scheme for Unique Pseudonymity within Zero Knowledge Proofs https://eprint.iacr.org/2022/1255.pdf chapter 3 page 14

Parameters​

message​

Field[]

sk​

PrivateKey

Returns​

Nullifier


fromJSON()​

static fromJSON(json: Nullifier): Nullifier;

Defined in: lib/provable/crypto/nullifier.ts:32

Parameters​

json​

Nullifier

Returns​

Nullifier

Overrides​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).fromJSON

sizeInFields()​

static sizeInFields(): number;

Defined in: lib/provable/types/provable-intf.ts:66

Return the size of the T type in terms of Field type, as Field is the primitive type.

Returns​

number

A number representing the size of the T type in terms of Field type.

Inherited from​

Struct({
publicKey: Group,
public: {
nullifier: Group,
s: Scalar,
},
private: {
c: Field,
g_r: Group,
h_m_pk_r: Group,
},
}).sizeInFields